Wennström Anders, Ericson Lars
Department of Ecological Botany, University of Umeå, S-90187, Umeå., Sweden.
Oecologia. 1994 Apr;97(3):407-411. doi: 10.1007/BF00317332.
In a greenhouse experiment, one isolate of the systemic rust fungus Puccinia minussensis was applied to the host clone from which it was collected and to four other clones of the host Lactuca sibirica. The plants were grown in fertilized potting compost (N+) to promote growth and in peat (N-) to hamper growth, for three growing periods during one year. The results show that the expression of host plant resistance could not be determined visually, but there were differences in effects on the clones. The rust isolate was found to produce a significantly higher percentage of diseased shoots on clone A (the clone it was taken from). Furthermore, the rust also had the strongest effect on both biomass and shoot production on clone A compared to the other four clones. The data suggest that the rust isolate is highly adapted to the clone from which it originated. We suggest that selection in this system has not favoured a benign pathogen and that similar patterns are likely to occur for plants that (i) rarely establish by seeds; (ii) have strong lateral growth; and (iii) may persist for long periods once established.
在一项温室实验中，将系统型锈菌小柄锈菌的一个分离株接种到采集该分离株的寄主克隆以及另外四个西伯利亚莴苣寄主克隆上。这些植株在添加肥料的盆栽混合土（N+）中生长以促进生长，在泥炭土（N-）中生长以抑制生长，为期一年，共经历三个生长阶段。结果表明，无法通过肉眼确定寄主植物抗性的表达，但对不同克隆的影响存在差异。发现锈菌分离株在克隆A（即采集该分离株的克隆）上产生的病枝百分比显著更高。此外，与其他四个克隆相比，锈菌对克隆A的生物量和枝条产量的影响也最强。数据表明，锈菌分离株高度适应其起源的克隆。我们认为，在这个系统中进行的选择并没有青睐良性病原体，对于那些（i）很少通过种子繁殖；（ii）具有较强横向生长能力；（iii）一旦定植可能长期存活的植物，可能会出现类似的模式。
